Very simple question 2 - Electronic Circuits Projects Diagrams Free

zambalik · 11th July 2003, 02:43 PM

hi
i am using IC HT 8870 as a DTMF to BCD decoder.
the question is when does this IC starts decoding, after picking up the phone or before while ringing ?
thanx

Sebi · 11th July 2003, 11:05 PM

The DTMF decoder working in sound frequecy range, after picking up.

zambalik · 12th July 2003, 12:47 AM

i didn't get u
does this mean it won't decode untill i pick up the phone ?

Yatin · 17th July 2004, 12:29 PM

The IC starts decoding when a valid tone pair is present on it's i/p
B T W i would like to know the proper R/C values as my 100k,100k,300k,0.1uc values do not show me data at all,even on StD pin

Thanx
Yatin

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11th July 2003, 02:43 PM	(permalink)
zambalik	Very simple question 2 hi i am using IC HT 8870 as a DTMF to BCD decoder. the question is when does this IC starts decoding, after picking up the phone or before while ringing ? thanx

11th July 2003, 11:05 PM	(permalink)
Sebi	The DTMF decoder working in sound frequecy range, after picking up.

12th July 2003, 12:47 AM	(permalink)
zambalik	i didn't get u does this mean it won't decode untill i pick up the phone ?

17th July 2004, 12:29 PM	(permalink)
Yatin	Really simple ! The IC starts decoding when a valid tone pair is present on it's i/p B T W i would like to know the proper R/C values as my 100k,100k,300k,0.1uc values do not show me data at all,even on StD pin Thanx Yatin